package designPattern.facade;

public class Screen {

    //使用单例模式,使用饿汉式
    private static Screen instance = new Screen();

    public static Screen getInstance(){
        return instance;
    }

    public void on(){
        System.out.println("screen on");
    }

    public void off(){
        System.out.println("screen off");
    }

    public void up(){
        System.out.println("screen up");
    }

    public void down(){
        System.out.println("screen down");
    }
}
